FIG. 1 is an example cross-sectional diagram illustrating a semiconductor device according to the related art.
Referring to FIG. 1, substrate 1 may be thermally oxidized to thermally grow pad oxide layer 2. Silicon substrate 1 may be etched to a prescribed depth to form trench 6 at a device isolation region. An oxide layer may be formed at trench 6 to obtain a shallow trench isolation (“STI”) structure.
However, in the related art, a bottom edge of an STI may be subjected to large amounts of stress during an ion implantation and high temperature annealing, which may be subsequent processes. In particular, an ion implantation may be performed using elements such as arsenic As, which may have a relatively large size. During ion implantation, a failure may occur. For example, a failure such as a fracture and/or hole 8 may occur. This may reduce a yield of semiconductor devices during manufacturing. Hole 8 may indicate a tearing of a substrate due to significant stress.